Businessman and aviator Dick Smith would not have a problem flying through the ash cloud from a Chilean volcano and says the decision to ground flights is an "ultra-conservative" move.

The disruption from the ash cloud has now hit Western Australia, with Virgin, Qantas and Jetstar all cancelling flights to and from Perth.

South African Airways has also suspended its flights in and out of the city.

The latest developments:

Tiger says its Tasmania services are cancelled and Perth services are under review

Jetstar cancels all its New Zealand, Tasmania and Perth flights for the day, and will resume Tasmania flights tomorrow

Qantas says Tasmania and Johannesburg services will run tomorrow, but New Zealand, Perth and Buenos Aires flights under review

Virgin suspends flights to and from Perth until further notice

Civil Aviation Safety Authority spokesman Peter Gibson says flight disruptions will continue for some days, with Tasmania likely to feel the effects of the Perth ash cloud later in the week.

Mr Smith says the airlines that have cancelled flights are being "ultra safe".

"It's not 'safe' or 'not safe' - nothing is safe. Safe means without risk, there's no such thing in life. It's degrees of safety," he said.

"Qantas are being ultraconservative, because how they've decided they want to be... first of all it's removing that tiny bit of risk and also it will give the public the impression they put safety foremost.

"I think it would be costing them money, but they've decided to be, in this particular case, ultraconservative.

"[Those that are flying] have decided not to be ultra safe. They've decided that the risk is very small, which it is."

Mr Smith, a former CASA chairman, says he would have no qualms about flying through the ash cloud.

"I'd fly in any airline which is flying at the moment, because I believe after the dust has gone two-thirds of the way around the world, that it's so spread out that it might have a long-term effect but I don't think it's going to have a short-term effect," he said.

"So I wouldn't have a problem in flying.

"If you fly straight through a plume above a volcano... that's quite different to dust which has gone two-thirds of the way around the world. That's proven in the fact that there are airlines still flying.

"No airline would ever fly through the plume of a volcano or close to it under any circumstances, but there are airlines that are happy to fly in the dust that's gone two-thirds of the way around the world.

"But I can understand [some airlines have] decided to be ultraconservative because they want to reduce the risk and they want to tell the public they are ultraconservative."

Impacts

Mr Smith says while the ash cloud may not cause short-term damage, it could have long-term impacts on aircraft.

"I think one of the other things the airlines are looking at is the long-term damage that can be done to their aircraft, not a short-term of the engines flaming out," he said.

"The only way the engine can flame out is if you fly directly through a volcanic cloud, which has happened a few times, but to get into some dust that has gone two-thirds of the way around the world is most likely to do some long-term damage to the aircraft, not the type of short-term that would make the [engine] flame out."

The ash plume is forecast to be as low as 15,000 feet and may remain in place for 24 hours.

Sally Cutter from the Volcanic Ash Advisory Centre says the lower band level does pose a risk.

"Volcanic ash makes it dangerous to fly, particularly for jet engines, due to the fact it can cause the engines to stop, so it's really up to each individual airline to assess the risk they're prepared to take," she said.

Moscow's words and actions — including the alleged poisoning of a former spy — are not the results of random aggression but rather fall into distinct patterns that can help us anticipate Russia's next moves under Vladimir Putin.